Answer:
The correct answer is D sister chromatids;centromere
Explanation:
After DNA replication during s phase or synthesis phase of interphase of the cell cycle,each chromosome has a copy and the cell that is newly formed is now 4n.
We cal these identical pairs sister chromatids and they are held together by a centromere
Photosphere,chromosphere and the corona
Answer:
False
Explanation:
The cells of collenchyma have evenly thickened cell wall
Please Mark me brainliest
Answer:
A) many noncoding stretches of nucleotides are present in mRNA.
Explanation:
A transcription unit in eukaryotes includes the region that code for mRNA extending from the 5' cap site to the 3' poly-A site. It also includes the controlling regions. The mRNA formed by transcription also has some non-coding intervening sequences. These are called introns. Introns are removed from the primary transcripts by the process of splicing that occurs after transcription.
Therefore, a transcription unit that is 8,000 nucleotides long may use only 1,200 nucleotides to code for a protein having 400 amino acids since the rest of the nucleotides are part of introns and are removed from mRNA after transcription.